Spain was warned to halt “provocative incursions” into waters around Gibraltar
on Thursday when its ambassador to London was summoned to the Foreign Office.

The diplomatic protest followed two “serious incursions” by Spanish state vessels in the waters around the British overseas territory on Tuesday – the latest in a series of spats over the Rock this year.

David Lidington, Britain’s Minister for Europe said a Spanish naval vessel had patrolled Gibraltarian waters for several hours and that a Spanish customs vessel had also attempted to seize a civilian boat off Gibraltar’s coast, forcing a Royal Gibraltar patrol boat to intervene.

”The UK has repeatedly made diplomatic protests to Spain over attempts by Spanish state authorities to exercise jurisdiction in British Gibraltar Territorial Waters,” Mr Lidington said in a statement.

”I condemn these provocative incursions and urge the Spanish government to ensure that they are not repeated,” he said.

Federico Trillo, who became Spain ambassador to London in May, was summoned by Permanent Under Secretary of State Simon Fraser to hear the complaint.

It emerged that Britain’s ambassador to Madrid was also summoned by Spain’s foreign ministry to hear Spanish complaints over the incident on Thursday morning, minutes after the request was made for Mr Trillo to attend the Foreign Office.

Giles Paxman, who has held the ambassador post in Madrid since 2009 , was unable to attend the meeting and sent his deputy, Daniel Pruce.

A Foreign Office source said: “It’s a clear case of tit-for-tat,” adding that “such action is extremely rare between Britain and Spain, two nations which normally enjoy good relations".

The rare summoning of Spain’s ambassador to face British displeasure marks an escalation in the long-running dispute over Gibraltar, a tiny peninsula on Spain’s southwestern tip that was ceded to the British under the Treaty of Utrecht in 1713.

Spain still claims sovereignty over the territory and does not recognise Gibraltar’s right to its territorial waters, which Britain says is guaranteed by UN law and a treaty between the two countries.

A ban on Spanish vessels entering the waters and a row over fishing rights has heightened diplomatic tensions between Spain and Britain in recent months, and led to Queen Sofia of Spain snubbing an invitation from the Queen during her Diamond Jubilee.

There have been several recent incidents in the disputed waters including a stand-off between a Spanish naval corvette and a British naval gun ship last week.

Following that incursion Gibraltar’s Chief Minister Fabian Picardo accused the Spanish Navy of “a scandalous and illegal act of aggression” and called on London to respond.

Spain lodged an official complaint over the visit of the Earl and Countess of Wessex to Gibraltar as part of the Jubilee year celebrations.

Three years ago Mr Paxman, Britain’s ambassador to Madrid was forced to apologise after the Royal Navy fired on a buoy bearing a red and yellow target flag resembling the Spanish national flag during target practice off Gibraltar.